How much is it important to avoid fold in metal forming

[LCform]

Hi All

My intention of the question is cold forming of bolts, where the folding could happen during the deformation of some complex shapes. how would it affect the behavior of the product. I mean at what point the overlap of the material on itself becomes undesirable ?

 

[BrianPetersen]

Illustration, please.

Thread rolling shouldn't cause any material to "fold".

The manufacturing methods for hex heads and socket heads and similar shapes are well established.

 

[LCform]

There are always possible folds like here :[link SIMULATION OF THE COLD FORGING PROCESS IN FASTENER MANUFACTURE]Link[/url]

I don't know what did you mean by being established, what about other shapes? if there is more variety of shapes ? I dont have examples at hand now, but my question was more qualitative, independent of a certain case

 

[3DDave]

Folding might or might not cause catastrophic failure.

Are you looking to justify shipping defective products or just to stop inspecting to see if the defects are there?

 

[LCform]

I would like to know in if you notice that there is a fold in a designed process, by which guidlines you might modify the design ? mechanical properties ? die wearing ?

 

[racookpe1978]

Without knowing the specific process, forming temperature and speed, and metal ... It's all just a guess.

So, "maybe" there will be folds. Do NOT blindly go off and believe simulations are the real world!